Car Porn

[6PAK72]

SR71 - now THERE's power-to-weight ratio!!!

[DanB]

The TR6 crank, with 7 bearings DAN,

Yer gonna have to show me some evidence on that. I'm pretty sure there's a main bearing up front (1), then crank throws 1&2, another main (2), two more throws, main (3), throws #5&6, then the rear main (4 total).
http://books.google.com/books?id=OOYnrK ... gs&f=false

has a tortional (roatational) vibration that starts up around 4500rpm, and gets really bad at 6000rpm. The "flex" whip-saws the flywheel, and at it's outer edge it oscillates nearly .5 inch!!! at 5000rpm. Kas Kastner discovered this in1969 at Daytona...very dramatic story.

On Z's, a lightweight flywheel and heavy harmonic balancer alleviate this issue to some degree. Without addressing this issue, Z's are limited to only ~7500-8000rpm depending on stroke

Dan, I was going to use the sleeve, but the tech line at ARP said most definitely do NOT do that.

ruh-roh...

They suggest a 7/16"d x .073 washer under the bolt head (3/4"), and they suggest not Loctite, but ARP Assembly Lock. Probably the same thing, but hey, they seemed to know what they were talking about.

More than I do, I'm sure.

The really fun part is that the transmission has to be removed from the TOP, not from underneath. So, the entire interior comes out.

Dayum.

Yup, that Miata is looking better all the time....

For a track car, no question a Miata is going to be a better bet than a TR-6. You will lose style points, though...

[DanB]

I would still highly recommend steel bushings for the aluminum holes. AND Loctited, properly cleaned/prepped/primered threads.

Dan, are you recommend steel bushing in the alum flywheel? Loss of clamping force due to differences in expansion rates of alum and steel?

Not anymore I'm not...

The idea was to do something to keep bolt tension and reduce bolt-head fretting into the aluminum due to crank torsional wiggly action. I wasn't too concerned with differential thermal expansion. The aluminum would expand more than the steel, so theoretically bolt tension should increase with temperature, but I seriously doubt it's much of an issue where the flywheel bolts to the crank. Although I do not have temperature data...

[Stynger]

SR71.....I did some work on the fuel probes.

Is that why they leaked?

[6PAK72]

Les, if YOU had worked at Coventry, they NEVER would have leaked!!

[6PAK72]

Dan, what was up with your Z? Did you get home OK?

[DanB]

The throttle linkage for the middle car slipped on the shaft, and that carb stuck partially open. I was driving my student around, and going into turn one I got little/no braking, yikes! Stiff pedal but very little deceleration. Fortunately there's still a lot of room to go QUITE deep there. Same symptom going into turn 3, stiff pedal, not much in the way of deceleration. Hmmm, thought I... I brought it into the pits, and it was there that I realized that the throttle was the problem as it was trying to idle at ~5000rpm.

Fixed the slipped linkage and threw the Hoosiers on it, but didn't start or drive the car (end of driver's school day). Next morning, the car didn't idle right, and it felt/sounded like it was down a cylinder. Anthony Quindazzi helped me try to diagnose it, we figured it must've been an ignition thing. But no... Unfortunately no one had a compression gauge, although it's probably better that they didn't as if I'd known the truth I might not have done the TT! I babied it for one timed lap and brought it in. Took it to Anthony's shop (A C Imports in Bedford, they specialize in old Z's), and lo and behold, pistons #3 and #4 were wrecked (ring damage, partial ventilation). Dayum...

Hard to believe that less than a lap running with that one carb stuck partially open could do that kind of damage :'(
Anyway, it's getting fixed and I should have it back on track for the September NHMS

So at least my unemployment $$$ is going to a good cause!

[brucesallen]

Need rev limiter?

[cuda6666]

Rev limiter, Bruce? Sounds like #3 and #4 were running lean because of the stuck linkage at the midle carb (whatever that is).

[DanDarcy]

I've seen a carb once they are kind of scarce

[breakaway500]

Nothing wrong with carbs.They just need a lot of TLC..and an occasional whack with a hammer...

[6PAK72]

Well, got the parts in the TR. Like Bruce says - NEED REV LIMITER - Damn that thing rev's FAST. Heel - Toe will be a bitch for a while. But, now the clutch pressure is sane and silky smooth. Amazing what several hundred in new parts will do.

Ran WGI with the NEQ and got solo'd! Started at 3:12 and ended up at 2:35

Jeff W. still ran over 10mph faster....I have a lot of learning to do!

As for the carbs, I got that worked out as well - it was actually the electronic ignition module missing at high rpm. Carbs were set fine. Dumped $500 down the toilet chasing that problem.

[breakaway500]

Glad to hear you got the TR sorted and those times are falling!

You ran with NEQ at WG earlier this week?So did I.. I saw Jeff,but did not see the TR-6. Where were you hiding?
Did you see the Ferrari 430 and the Lambo Gallardo?

Photo opportunity!

[DanDarcy]

Hi Jeff & Liz -- I ran the NEQ event this past Monday and Tuesday also. Mark and I drove up together. I didn't see the TR either . What were you driving. I had the black Mustang with the white number ovals #310 ran in the black group. I wish I had known you were there, I've been hoping to me you.

[6PAK72]

We saw the Miata and waved, and I thought I saw the 'Stang. You were running red group right? I spent some time up on the hill wathching people's lines through the "s" turn and saw the Lambo and several Z60's, as well as a few other nice toys.

The TR is still vibrating, so we were in our "new" '91 Miata in Green rungroup - I FINALLY got solo'd!!!!! YaHOOOOO!!!!

Also, I have discovered the joys of sliding through the bus stop and paying attention to apex's - the shot shows all the cars that I consistently beat through there, lead them down the hill, and only that BMW passed me up the hill coming out - the MR2 was not even on the planet.